\clearpage
\onecolumn
\begin{center}
\appendix
\section{Event Log File}\label{app:el} 
\includegraphics[width=0.8\textwidth]{eventLog}
%~\ref{app:el}

\clearpage
\section{Ballot Image File}\label{app:bi}
\includegraphics[width=0.9\textwidth]{ballot}
%This is app~\ref{app:bi}

\clearpage
\section{System Log File}\label{app:sl}
\includegraphics[width=0.9\textwidth]{system}
%This is app~\ref{app:sl}
\end{center}
